{"id":342182,"date":"2026-03-16T14:41:10","date_gmt":"2026-03-16T14:41:10","guid":{"rendered":"https:\/\/www.newsbeep.com\/il\/342182\/"},"modified":"2026-03-16T14:41:10","modified_gmt":"2026-03-16T14:41:10","slug":"shape-shifting-peptide-material-controlled-by-humidity","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/il\/342182\/","title":{"rendered":"Shape-shifting peptide material controlled by humidity"},"content":{"rendered":"

A porous, peptide-based material reconfigures its 3D structure<\/a> in response to small changes in temperature and humidity (Matter 2026, DOI: 10.1016\/j.matt.2026.102669). The different crystal forms exhibit contrasting mechanical properties\u2014most notably shifting from a stiff, hexagonal lattice to a soft, layered structure\u2014potentially opening the door to stimuli-responsive applications in areas such as separation and filtration.<\/p>\n

The properties (and therefore function) of any material depend heavily on its structure. Biology has mastered the art of interconverting between closely related forms\u2014such as open and closed ion channels\u2014but human engineering still lags somewhat. \u201cMost human-made materials are static, and there are not very many examples that can reversibly respond in the solid state,\u201d says Rein Ulijn<\/a>, a bionanoscientist at the City University of New York (CUNY).<\/p>\n

Inspired by leucine zippers<\/a>\u2014structural motifs that zip proteins together\u2014Ulijn and mechanical engineer Xi Chen<\/a>, also at CUNY, tried to replicate this kind of dynamic behavior. They created four leucine-isoleucine dipeptides, then combined them in solution. By slowly removing the excess water, the pair induced the dipeptides to form a solid, porous crystal hydrate with a stiff, 3D honeycomb structure. \u201cThe driver of the assembly is the hydrophobic effect,\u201d Ulijn says. \u201cLeucine and isoleucine are among the two most hydrophobic amino acids. So when you put these in water, they very quickly aggregate together to exclude water, and then they reorganize into a hydrogen-bonded network.\u201d<\/p>\n

Crucially, the small amount of water confined within this network dictates the orientation of the conformationally flexible amino acid side chains. In the initial honeycomb structure, the leucine and isoleucine side chains create a hydrophobic column, and a corresponding hydrophilic, water-filled channel at 90\u00b0 to the hexagonal lattice. But gently removing water (by heating it to 60 \u00b0C and reducing humidity to 50%) triggers a rotation in these peptide side chains; that causes the hydrophobic columns to align in parallel to the water-filled channels while retaining the honeycomb structure. Further water loss at 70 \u00b0C and 50% humidity triggers a more substantial reorganization to a softer structure in which the side chains form a hydrophobic cavity that separates the layers of dipeptide.<\/p>\n

The water not only maintains the structure of the material \u201cbut also acts as the fuel to drive the phase transition,\u201d Chen says. \u201cThe leucine-isoleucine crystals have multiple, very shallow energy landscapes. Changing the temperature and humidity allows us to change the chemical potential and access those different energy landscapes and their corresponding distinct phases.\u201d<\/p>\n

The low energy barrier and mild conditions make each transition completely reversible, and the team successfully interconverted between the stiff honeycomb and soft layer structures over multiple cycles. Real-world applications for this material are still a long way down the line, but Chen and Ulijn think the concept could be useful in barrier and coating materials\u2014particularly in products, such as food packaging, where there\u2019s a need to restrict humidity.<\/p>\n

In the meantime, the team remains focused on developing deeper insight into the fundamental principles behind their dynamic material. \u201cWe would like to understand better how we can design and optimize these systems further, and ultimately rationally create architectures that can switch in predictable ways,\u201d Ulijn says.<\/p>\n

\n Chemical & Engineering News<\/p>\n

ISSN 0009-2347<\/p>\n

Copyright \u00a9
\n 2026 American Chemical Society<\/p>\n","protected":false},"excerpt":{"rendered":"A porous, peptide-based material reconfigures its 3D structure in response to small changes in temperature and humidity (Matter…\n","protected":false},"author":2,"featured_media":342183,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[28524,4070,85,46,137182,141,167425],"class_list":["post-342182","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-biobased-materials","tag-crystals","tag-il","tag-israel","tag-peptide","tag-science","tag-shape-shifting"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/342182","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=342182"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/342182\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/342183"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=342182"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=342182"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=342182"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}